矿井电网单相接地选线方法实现

Single Phase Grounding Selection Method and Realization in Mine Electric Power Network

针对国内矿井电网多数采样三相中心点不接地供电方式中对于电网的单相小电流接地较难判断的问题,借鉴中心点非直接接地高压电网的小电流接地选线理论和解决方案,结合矿井电网的特点,采用SIMULINK建立矿井电网仿真模型,仿真结果表明故障线路的故障相容性电流是正常线路倍数关系;提出了基于线路容性电流大小的变化特性与传统的零序功率方向相结合的综合故障选线方法,并设计了采用电力测量DSP与单片机相结合的双CPU故障选线保护装置,以解决矿井低压电网故障选线问题。

According to the difficult judgment problem of the single phase small current grounding in the major sampling three phase center no grounding power supply mode of the mine electric power network in China,with the references of the small current grounding line selection theory and solution of the center indirect grounding high voltage power network,in combination of the mine power network features,the SIMULINK was applied to establish the simulation model of the mine electric power network.The simulation results showed that the fault compatibility current of the fault line would be more times higher than the normal line.Based on the variation features of the line compatibility current and the traditional zero sequence power direction combined comprehensive fault line selection method,a double CPU fault line selection protection device combined with the electric power measuring DSP and the single chip processor was designed to solve the fault line selection problems of the mine low voltage network.